A Brucella virulence factor targets macrophages to trigger B-cell proliferation.

J Biol Chem

Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, IIB-INTECH, National Research Council of Argentina (CONICET), Universidad Nacional de San Martín, San Martín 1650, Buenos Aires, Argentina.

Published: July 2013

Brucella spp. and Trypanosoma cruzi are two intracellular pathogens that have no evolutionary common origins but share a similar lifestyle as they establish chronic infections for which they have to circumvent the host immune response. Both pathogens have a virulence factor (prpA in Brucella and tcPrac in T. cruzi) that induces B-cell proliferation and promotes the establishment of the chronic phase of the infectious process. We show here that, even though PrpA promotes B-cell proliferation, it targets macrophages in vitro and is translocated to the cytoplasm during the intracellular replication phase. We observed that PrpA-treated macrophages induce the secretion of a soluble factor responsible for B-cell proliferation and identified nonmuscular myosin IIA (NMM-IIA) as a receptor required for binding and function of this virulence factor. Finally, we show that the Trypanosoma cruzi homologue of PrpA also targets macrophages to induce B-cell proliferation through the same receptor, indicating that this virulence strategy is conserved between a bacterial and a protozoan pathogen.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3711288PMC
http://dx.doi.org/10.1074/jbc.M113.453282DOI Listing

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